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III. General Characteristics of Modern Farming
It. W. EtURLBUT
comparative values are 1058,1066, and 1064, respectively. On this basis,
it is evident that whereas we North Americans have been successful in
making it possible for one worker to accomplish much more than i n other
parts of the world, we have not been so successful in increasing the yields
3. Inzpwt of a 20 Per Cent Increase i n Total Farm Ozltptlt
A summary of reports of forty-eight state committees, United States
Department of Agriculture Information Bulletin 88 (1952), appraising
the productive capacity of agriculture during a subsequent five-year
period, indicates that a total farm output about 20 per cent greater than
that of 1950 could be attained under “average” or reasonably favorable
conditions. It is further estimated that about 44 per cent of the projected increased output potential exists in the South, about 41 per cent
in the North Central Region, and about 5 per cent each in the Northeast,
Mountain, and Pacific regions.
Production of feed and livestock would be expected to make u p a
major part of the increased output in all regions and 58 per cent of the
increased production for the country as a whole. Food grains would
represent about 15 per cent of the projected increase for the nation as a
w:iole; fruit, truck, and vegetable crops, about 9 per cent; and cotton,
about 5 per cent.
A projected increase of 20 per cent above the total farm output in
1950, without a substantial increase in the farm labor force, is estimated
to require about five or six times as many cotton pickers ; more than twice
as many forage harvesters ; 30-50 per cent more balers, power sprayers,
beet harvesters, and power manure loaders ; 20-25 per cent more mechanical corn pickers and combines; and about 13 per cent more milking
machines and silos. These estimates do not include the need for machines
to replace those discarded because of wear or obsolescence.
It is estimated that a 70 per cent increase in commercial fertilizer
would be required to help produce the projected increases in yield. The
estimated potential maximum yield per acre of major crops and pasture,
as a percentage of the 1950 yields (adjusted), is corn, 167 per cent;
sorghum for grain, 124 per cent ; soybeans, 141 per cent ; peanuts (picked
and threshed), 183 per cent; cotton (all), 176 per cent; wheat (all),
140 per cent; rice, 120 per cent, hay (all tame), 156 per cent, rotation
pasture, 197 per cent. Although these production estimates bear both
theoretical and practical implications, they do show a relatively wide
gap between current crop yield expectancy under prevailing .practices and the yields that could result if farmers were using the known
improvements that would be profitable under reasonable economic condi-
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tions. This gap presents a real challenge to agricultural research, education, and extension programs. On the other hand, the fact that the
estimates indicate a practical total agricultural output of one and onehalf times that of the record year 1951 is, in itself, a real tribute to
agricultural research. It also is good evidence that modern American
agriculture is the most dynamic the world has ever known.
Farming tomorrow must be done more scientifically, and more precisely, than it was yesterday. This means that in the future even more
emphasis must be placed on increased production, improvement in quality of products, better management, better equipment, and better living
conditions for farm people. Better control over the factors influencing
agricultural production will continue to be the principal joint objective
of agricultural engineers and agronomists.
4. A Pew Important Developmennts, 1900-1950
The record of new developments during the past fifty years makes it
seem almost futile to attempt to forecast developments or trends beyond
the next decade. As a prelude to consideration of trends in agricultural
production, it seems proper to review briefly a few of the results of our
efforts to gain a more abundant life during the past fifty years. We
already are taking for granted some of these relatively new developments which have exerted and still are exerting a tremendous influence
on our well-being and on our pattern of life. Although the basic inventions of these developments were of earlier conception, their practical
applications have come in recent times. A few of these developments are :
1. The use of power and machinery in agriculture, which has reached
the point where 85 per cent of the people in the United States have been
released from the task of producing food. This has made possible our
great industrial development and the correspondingly great increase in
2. Telephones and other means of direct communication, which multiply human contacts and speed u p business transactions.
3. Motion pictures with sound and radio and television, which serve
well for disseminating information and providing entertainment.
4. Airplanes, which are now beginning to play a n important part in
5. Electricity, for light and power, now provided on a high percentage of the farms in the United States.
6. Mechanical refrigeration for the preservation of the perishable
7. Pavement on the main routes used by vehicles.
L. W. HTJRLBUT
8. Hybridization in farm crops and greatly improved breeding and
feeding practices i n the animal enterprises.
9. Widespread use of chemical fertilizers.
10. Basic practices for use in reducing water runoff and the closely
related erosion of soil.
11. Transportation of liquid fuel over long distances in pipe lines.
12. Development of water resources for irrigation.
What will be the comparable developments in the second half of the
century? Is it proper to say that new developments will come as rapidly
and be of more beneficial influence than those of the first half of the
century ? Some people are inclined to think that technological advances
are f a r outdistancing the developments in the social structure of the
world. Certainly we cannot overlook the importance of the “human factor” in considering future developments. However, there is little concrete evidence to indicate that both technological and social advances
will not continue a t an accelerating rate.
1. Farm Power
A t least two kinds of power are available on about 88 per cent of the
farms in the United States, namely, mechanical power and electrical
power. Although both sources of power are very useful, both have certain limitations.
a. Tractor Power. Tractors of today have too few power outlets, and
as a result they frequently remain idle while the operator serves as a
source of power. On the other hand, electric power can be applied to
many jobs on the farm, but it is limited to a n area around the meter
pole approximately 400 feet in radius. Another limitation on the use
of electric power furnished by rural lines is unscheduled interruption
of the supply. The limitations now recognized in the two power sources
for the farm indicate that a combination might be most useful. An
engine-electric tractor would have numerous power outlets ; it would
make some of the automatic features of electric power useful on field
machines; and it could serve as standby power in case of interruption
of the electric service,
The electrical generator and the electrical motors required for use in
an engine-electric power system present some difficult design problems,
but the problems appear to be subject to reasonable solutions. The cost
of such a system appears to be an unreasonable handicap until the pres-
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ent investment in engine-units standing idle on idle farm machines is
One manufacturer has recently introduced a transport-type tractor,
shown in Fig. 1, to be used interchangeably with a two-row corn pickersheller and a grain combine. These harvesting machines are mounted
and dismounted on the tractor by the aid of a hoist-frame and iron transport wheels for each of the units.
Manufacturers are now concentrating heavily on the development of
hydraulic systems for use in steering, for use in mounting and dismounting implements quickly and easily, and to serve as a substitute for hand-
FIQ.1. A picker-sheller, mounted 011 a t.ransport-type tractor. The tractor can
also be used to transport a combine. The manufacturer claims that changing the
attachments requires only about 30 minutes. (Courtesy of Minneapolis Moline
lever controls. I n a few instances, electrical controls are combined with
hydraulic control systems. I n order to keep the fuel-use efficiency of
the tractor engine high, some of the manufacturers are providing a means
f o r disconnecting the drive to the hydraulic pump when it is not needed.
Methods for changing the drive-wheel spacing semiautomatically on
row-crop-type tractors are being provided by a few manufacturers.
Lack of good stability in the high-clearance row-crop-type tractor is
causing both manufacturers and safety specialists considerable concern.
Only two solutions have been proposed, first, the development of farming systems which eliminate tractor work in row crops and, second, that
of easily operated devices for spreading the tractor wheels laterally so
L. W. HURLBUT
that they will provide greater stability in the tractor while it is not
being operated in row crops.
It appears that in the near furture most of the tractors will be built
in compliance with the ASAE-SAE standard specifications (1944) for
power take-off and drawbar hitch location and construction. Compliance with these standards makes it' possible for the operator to use any
make of power take-off driven machine with any make of tractor. The
standards also include specifications for providing and connecting the
shields along the power-shafting.
b. Electric Power. Electricity will, undoubtedly, find much greater
use on American farms during the next decade. The number of uses
for electricity on the farm increased from about 35 in 1925 to more than
250 a t present. The number of domestic uses are greatest a t the present
time, but near that number are the uses in crop, animal, and poultry
production. It appears that electric power on the farm will help to
make crop-drying practical, and that in turn may result in important
changes in some grain and hay harvesting and storage practices.
The heat pump provides one of the most challenging and interesting
applications of rural electric power yet developed. The heat pump, as
the name implies, can be used to transfer heat into or out of a given
space. I n the farm home or other buildings it would provide heat during
the cold season and remove excess heat during the warm season. However, before the cost of this equipment and its operation can be reduced
to the economical range for general use, several technical mechanical
and electrical problems must be solved. Johnson (1951) discusses such
problems and, i n addition, proper heat source, house design, reliability,
and serviceability. It is quite possible that widespread use of the heat
pump may develop during the next decade.
0. The Airplame. As a source of power for executing agricultural
operations, the airplane will undoubtedly come into much greater prominence during the next decade. More economical and effective dispersing of dusts, fertilizers, seeds, and sprays by aircraft is indicated in
research results being obtained by the Texas Engineering Experiment
Station (1952). The first phase of the research culminated in the design
and construction of an experimental airplane (Fig. 2) that is designed
to meet the requirements specified by agricultural pilots,
Lehmann (1952) assembled information on the agricultural use of
airplanes. His report indicates that about 5,000,000 acres of farm land
were treated in California by aircraft in 1951. The area treated was
almost double that treated the previous year. The Kansas reports
showed an increase from 419,500 acres in 1948 to an estimated 1,000,000
acres in 1950. There have been similar increases in other areas,
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FIQ.2. An experimental airplane designed to meet the requirements specified by
agricultural pilots. Provision is made f o r a quick change of equipment in preparation
for either dusting or spraying. (Courtesy of Texas Agricultural Experiment Station.)
2. #oil and Water Management
It is a well-recognized fact that variations in weather have a great
influence on the yield of crops. Thus far enough has been learned about
this problem to indicate ways in which the farmer may, in a measure a t
least, reduce the damaging effects of weather irregularities. Such measures include drainage, irrigation, improved infiltration and water-holding capacity of soils, and advanced practices for conserving the top soil.
a. Surface-Mulch Farming. The ways in which crop residues on the
surface of the soil aid in maintaining a high water-infiltration rate, the
conditions under which they reduce evaporation, the extent to which
they prevent soil loss, and the extent to which they influence crop yields
as compared to other methods of soil management, are subjects that
have been discussed by Dnley and Russel (1939, 1942a, 1947, 1948),
Carter and McDole (1942), and Larsen and Joy (1943). Mulch farming
and related machinery problems have been discussed by Duley and Russel (1942b) and Hurlbut (1950).
I n the surface-mulch farming system, one can quickly recognize all
of the perpetual machinery problems involved in providing time-tested
practices of good crop husbandry plus the problem of working through,
and under, a cover of crop residue. I n general, this practice appears best
adapted to relatively dry or warmer areas, where a small delay in planting time is less serious than in areas with a shorter growing season.
There are a t least two basic problems involved in utilizing crop residues for mulches, and, as one might expect, both of them have agronomic
and engineering implications. They are :first, to provide as good a seedbed a t seeding time as can be had with timely plowing and the usual
L. W. HURLBUT
secondary tillage operations ; second, to keep the crop residue on or near
the surface of the soil during the sequence of tillage and seeding operations.
The widespread interest of farmers and the active research in mulchfarming indicate substantial adoption of this practice in the future. One
prominent manufacturer is marketing a new stubble-mulch tiller for the
first time in 1953. Poynor (1950) reported the development of this new
tiller (Fig. 3), a multiple-purpose machine designed for use in row
FIG.3. An experimental machine designed for tilling, fertilizing, and seeding
in one operation. The front tillage units are designed t o loosen soil beneath a cropresidue cover and deposit chemical fertilizer in bands. The rear unit consists of
equipment8 for seeding and depositing starter-fertilizer near the seed. (Courtesy
of International Harvester Company.)
crops. It is designed to perform basic tillage, planting, cultivating, and
fertilizing operations. This development also indicates that a serious
effort is being made on the part of industry to simplify the machinery
requirements for producing row crops.
b. Runoff-Water-Control flystems. Advanced engineering techniques
for design of runoff-water-control systems are being studied. New techniques give some promise of reducing the cost of terrace systems and
indicate that such systems can be made more compatible with mechanized farming operations. Farm water-control systema are of the perma-
PROQRESS IN AQRICULTURAL ENQINEERING
nent type and have a considerable influence on farming efficiency. They
deserve the attention of a competent designer.
Wittmuss (1950) studied the design of terrace systems on five farms
and found that by relocating terraces, using variable slope in terrace
channels, and relocating waterways, he could accomplish a 28 per cent
(average) reduction in irregular areas; a reduction of 6.6-15.4 per cent
in terrace length required per acre in four out of five fields studied; and
a 28 per cent reduction in length of waterways required per acre. These
data indicate that water-control systems for land areas being operated
under close economic limits should be planned in accordance with good
engineering practices. This means that carefully prepared plans and
design details should be completed prior to the time construction is
c. Irrigation. The real meaning of the term “irrigation farming”
is becoming clearer each year as the results of irrigation research are
compiled and analyzed. It means something more than merely supplementing rainfall. Land and water are two costly resources i n irrigated
areas, and the development of both of them requires special planning in
order that optimum returns may be obtained. The basic decision a
farmer considering irrigation must make rests on whether or not he
wants to become an irrigation farmer. The decision does not rest on
whether or not to build a system that will supply additional water for
his crops. There is a big difference between these two considerations.
Basically the principles of irrigation farming in subhumid areas are
the same as those developed for arid areas, even though somewhat different problems are encountered. The basic requirements from the standpoint of resources are to maintain an optimum level of fertility, to
maintain good soil tilth so that the soil will respond favorably to water,
and to apply the optimum amount of irrigation water on a timely basis.
There is some evidence in recent irrigation research a t the Nebraska
Agricultural Experiment Station that timeliness in irrigation may be
a factor of considerable importance. This is based on the observation
that the efficiency of irrigation in Nebraska is now about 25 per cent
and on the reasoning that if irrigation efficiency could be increased to
50 per cent, it would be possible to double the present usefulness of
water resources. Increased knowledge of the timeliness factor may be
an important step toward this goal. Studies of the timeliness factor are
now under way at several experiment stations.
Some basic research is being devoted to methods of water application,
considering not only the mechanics of water distribution but also the
problem of soil conservation as it is related to methods of irrigation.
L. W. HURLBUT
Erosion on irrigated lands is a factor that has not yet received the
attention it deserves.
All evidence available indicates a large expansion in irrigated acreages during the next decade. Good irrigation farming is scientific farming of the highest order.
3. Harvesting a.nd Storing Grain
Maximum harvests rather than maximum yields are what the growers
want. Tremendous harvesting and storage losses are reported each year
because of deficiencies in harvesting practices and storage practices.
This area offers the agricultural engineer one of his greatest opportunities to increase efficiency in agricultural production. Agronomic research has been very successful in increasing crop yields and has
advanced much farther than has the agricultural engineers’ knowledge
of harvesting and storage requirements.
a. Some Harvesting and Storage Losses. Fenton and Swanson (1932)
report that replies received from 297 farmers indicated that 60 per cent
of them had suffered damage to wheat in farm storage. The average
amount damaged per farm was estimated a t 1000 bushels. If we consider the four-year period 1927-1930, the amount of wheat unfit for milling arriving from Kansas a t terminal markets varied from 1 bushel in
8 in the years with favorable harvesting weather to 1bushel in 4 in the
unfavorable years. Although this grain is not a complete loss, it is subject to a substantial discount.
Lemley (1951) verbally reported that of 10,037 bins of farm-stored
wheat sampled in 1950 in Nebraska, 1190 were declared ineligible for
loans at the outset because of excess moisture, sprouts, or “sick wheat.’’
During a reinspection in November and December, 334 loans on wheat
which contained about 13.5 per cent moisture were called up for payment because the grain was deteriorating rapidly. These data indicate
that about 15 per cent of the wheat was stored at a moisture level too
high for safe storage. It is not uncommon for farmers to store only the
driest wheat harvested.
Quisenberry (1949) indicates that annual grain losses in the United
States have been estimated at 10-15 per cent of the crop, although no
exact figures are available. He refers to estimates of the Food and Agriculture Organization which indicate that the present world losses of
grain in storage amount to about 26 million metric tons, roughly equivalent to 950 million bushels of wheat per year, or about 6.6 per cent of
the total cereal production of its forty-eight member countries.
The losses of corn occurring in the field and in storage are of considerable economic importance. When ear corn reaches the level of
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moisture safe for cribbing, the “normal” (expected minimum) field
losses, consisting of shelled corn and ears dropped, increase a t a rate of
about 3 per cent per week f o r a period of about four weeks, with the loss
thereafter increasing a t a rate of about 1per cent per week. The normal
loss a t the earliest safe cribbing time seems to be near 4 per cent. The
expected grain losses, under favorable harvesting conditions, are shown
in relation to kernel and cob moisture content of ear corn. Table I is
based on data reported by Shedd (1933), Smith e t al. (1949), and Kiesselbach (1950), and on unpublished data recorded by Arms and Hurlbut
of the University of Nebraska.
Expected Total Field Loss (Per Cent) of Corn Harvested under Favorable Conditions in Relation to Moisture Content of the Kernels and Cobs
Days after maturity
Kernel moisture, %
Cob moisture, %
Expected field loss
Normal harvest starts at a kernel moisture of 20 per cent.
The amount of damage that occurs to ear corn in storage is not easily
determined because of the large variation in results obtained in different
years. Shedd (1946) studied the effect of moisture content on grades
of corn in crib storage during the period 1937-1946. He found that the
percentage of cribs containing corn with 20.1 per cent moisture or less
varied from year to year as follows : 1937-38, 90 per cent; 1938, 100
per cent; 194041, 89 per cent; 194142, 85 per cent; 1944-45, 35 per
cent; and 194546, 19 per cent. He observed that it is under favorable
conditions only that a moisture level of 20 per cent will assure the production of grade No. 1 or No. 2 by the customary methods of crib storage. The corn stored at 20 per cent moisture or less, in the 360 cribs
observed, graded as follows (on a damage basis only) : No. 1, 36 per cent ;
No. 2, 26 per cent; No. 3, 14 per cent; No. 4, 12 per cent; No. 5, 6 per
cent; and sample grade, 6 per cent. Loss of some of the original good
quality of ear corn subsequent to harvest results from a lack of ventilation. Poor ventilation may be caused by imperfect machine husking
as well as by imperfect storage structures.
Field and storage losses in the production of grasses and legumes are
generalIy recognized as being rather high. The importance of these field
losses is indicated by Grandfield (1951), who collected data from widely
L. W . HURLBUT
scattered fields of alfalfa in Kansas. He found that with the present
farm methods of harvesting the seed loss ranged from 17 to 46 per cent.
On the other hand, Hanson and Harrison (1950) report that with present
harvesting methods farmers save only about 40 per cent of the alfalfa
seed actually produced.
There is evidence to indicate that grain producers have always been
reluctant to let grain crops stand in the field until they have dried naturally to a moisture content safe for storage. They have made use of
the header, the binder, the swather, and the corn crib as intermediate
steps in their efforts to reap crops at the earliest possible time. These
intermediate harvesting measures and the lack of a continuous and
easily controlled source of power on the farmstead apparently have not
been conducive to the development of equipment and structures suitable
for curing the crops after they have been placed in bulk storage. However, these measures do indicate that the grower considers a n early harvest of considerable economic importance.
Briefly, an important limiting factor in modern grain production is
the inadequacy of 19th-century storage structures used in combination
with 20th-century harvesting machines. At the present time, it appears
that forced-air drying will be a t least a partial answer to this problem.
The problem of harvesting and drying grain containing more moisture
than is permissible for safe, long-time storage is bounded by agronomic
factors governing the time of harvest and by pathologic factors governing the environment in storage. Basic factors to be considered in addition to maturity of the grain and character of the air available are
moisture and temperature of the grain, soundness of the kernels, foreign
material present, and the period of time suitable for drying.
6 . Moisture Limits for Some Harvesting Mwhines. Field tests conducted a t the Nebraska Agricultural Experiment Station during the
period 1948-1951 have demonstrated that the present-day combines and
corn shellers will do a reasonably good job of harvesting oats, wheat,
brome grass, legumes, and corn containing 25 per cent moisture. Wheat
has been combined at 28 per cent moisture ; oats, brome grass, and sweet
clover a t 32 per cent moisture, and corn containing u p to 30 per cent
moisture has been picked and shelled with an improvised trailer-mounted
Harold Hummel, a farmer near Fairbury, Nebraska, combined a
3-acre field of brome grass mixed with alfalfa which yielded seed containing about 51 per cent moisture. The seed from another 5-acre field was
harvested with 46 per cent moisture. About 200 bushels of this seed
was dried with unheated air to 12.2 per cent moisture in 84 hours of
fan operation spread over a period of ten days. The seed was dried in